The present invention relates to a method for manufacturing a short-circuit member for short-circuiting predetermined commutator pieces, a method for manufacturing a commutator, and an apparatus for manufacturing a short-circuit member.
In the prior art, an armature for a motor having power feeding brushes may include a commutator in which a plurality of commutator pieces are short-circuited. Such a motor allows electric current to flow even to commutator pieces that are not in contact with power feeding brushes by short-circuiting predetermined commutator pieces. This enables a reduction in the number of power feeding brushes required in the motor.
In one example, in a rotation machine described in Japanese Laid-Open Patent Publication No. 2000-134873, short-circuit wires for short-circuiting commutator pieces are arranged on an end portion of a commutator.
However, when the short-circuit wires are arranged on the end portion of the commutator, the short-circuit wires may rub against one another or the short-circuit wires may rub against coils and cause an electric connection (layer short-circuiting). This would lower yield during the manufacturing of the armature or cause erroneous operation.
Therefore, for example, short-circuit conductors may be formed by punching a conductive plate, and the short-circuit conductors may be embedded in resin material to form a short-circuit member. However, even in such a case, when filling a mold, which accommodates the short-circuit conductors, with molten resin material, the pressure produced deforms the short-circuit conductor. This may cause layer short-circuiting.